OnSIP

OnSIP is a leading provider of real-time communications services to businesses.

Headquartered in Manhattan, [OnSIP](http://www.onsip.com) is a powerfully simple Unified Communications as a Service (UCaaS) and collaboration platform for over 70,000 customer accounts. OnSIP Business VoIP customers enjoy the benefits of an on-demand phone system without the traditional high cost, burden, and inflexibility. The company also offers APIs for developers to rapidly and affordably build voice, video, and messaging applications of their own. OnSIP was founded on the premise that the future of business communications would rely heavily on IP technologies. Privately held with no outside investment, the company is managed by internet veterans who previously built one of the largest Internet Service Providers in New York City, Interport Communications, before it was purchased by RCN.